engleski

X-ray diffraction and57Fe Mössbauer spectra of the system Fe2O3-Ga2O3

The influence of gallium substitution on the chemical and structural properties of haematite, α-Fe2O3, has been studied using X-ray diffraction and57Fe Mössbauer spectroscopy. The presence of only α-(GaxFe1-x)2O3 phase is detected for the compositions with x between 0.01 and 0.90. A gradual decrease of the unit-cell parameters of α- (GaxFe1-x)2O3 with the increase of gallium substitution is measured.57Fe Mössbauer spectra showed that the value of the magnetic hyperfine field of pure α-Fe2O3 decreases with increasing gallium for iron substitution. The hyperfine magnetic structure, which is observed for α- (GaxFe1-x)2O3 at room temperature, collapsed for the composition with x≃0.50. The changes in the57Fe Mössbauer spectra of the α-(GaxFe1-x)2O3 phase are discussed in the sense of the electronic relaxation and the superparamagnetic effects.

X-ray diffraction ; Mossbauer spectroscopy ; Hematite ; Gallium substitution ; Solid-solutions

nije evidentirano